In 2007-2009, at the Experimental Agricultural Station in Lipnik near Stargard Szczeciński, a field experiment was performed on acid brown soil of the good wheat complex. This soil in the topsoil contained 8.2 g kg-1 of organic C, had a slightly acid reaction and a low contents of available forms of P (30.1 mg kg-1) and K (45 mg kg -1). During the growing season the ground water level re-mained below 3.0 m.The aim of the studies was to compare the yield potentials of corn and two hybrids of sweet sorghum cultivated in conditions of various humidity of the light soil. On the plots with and without drop irrigation, sweet sorghum (the Sucrosorgo-506 and Rona-1 varieties) and corn (the variety Oldham FAO-250), of which the latter was the species compared. The times and doses of irrigation were determined based on indications of soil tensiometers. To the irrigation a dropping line of a capacity of 2.4 l h-1 of water and emitters spaced 30 cm apart was used. The combined doses of water depended on the timing and amount of rain-falls and were: in 2007 - 40 mm, in 2008 - 150 mm, in 2009 - 110 mm. The plant density ...
